Semiconductor devices having work function metal films and tuning materials

A semiconductor device comprising:

• a first fin-type transistor comprising a first fin, a first trench on the first fin, a first dielectric film extending along inner walls of the first trench and a first work function metal film in the first trench, the first work function metal film being of a second conductivity type;
• a second fin-type transistor comprising a second fin, a second trench on the second fin, a second dielectric film extending along inner walls of the second trench and a second work function metal film in the second trench, the second work function metal film being of the second conductivity type;
• and
• a third fin-type transistor comprising a third fin, a third trench on the third fin, a third dielectric film extending along inner walls of the third trench and a third work function metal film and a fourth work function metal film sequentially provided in the third trench, the third work function metal film being of a first conductivity type and the fourth work function metal film being of the second conductivity type,
• wherein no work function metal film of the first conductivity type is between the first dielectric film and the first work function metal film or between the second dielectric film and the second work function metal film, and
• wherein the first dielectric film comprises a work function tuning material and the second dielectric film does not comprise the work function tuning material.

A semiconductor device comprising:

• a first fin-type transistor comprising a first fin, a first trench on the first fin, a first dielectric film extending along inner walls of the first trench and a first work function metal film in the first trench, the first work function metal film being of a first conductivity type;
• a second fin-type transistor comprising a second fin, a second trench on the second fin, a second dielectric film extending along inner walls of the second trench and a second work function metal film in the second trench, the second work function metal film being of the first conductivity type;
• and
• a third fin-type transistor comprising a third fin, a third trench on the third fin, a third dielectric film extending along inner walls of the third trench and a third work function metal film in the third trench, the third work function metal film being of the first conductivity type,
• wherein an oxygen concentration in the first work function metal film is lower than an oxygen concentration in the second work function metal film, and
• wherein a first thickness of the first work function metal film is different from a third thickness of the third work function metal film.